function twentyseventeen_customize() {
  wp_die(
    sprintf(
      /* translators: %s: The current WordPress version. */
      __( 'Twenty Seventeen requires at least WordPress version 4.7. You are running version %s. Please upgrade and try again.', 'twentyseventeen' ),
      $GLOBALS['wp_version']
    ),
    '',
    array(
      'back_link' => true,
    )
  );
}